[en] Safety indicators play a role in providing information on organizational performance, motivating people to work on safety and increasing organizational potential for safety. The aim of this report is to provide an overview on leading safety indicators in the domain of nuclear safety. The report explains the distinction between lead and lag indicators and proposes a framework of three types of safety performance indicators - feedback, monitor and drive indicators. Finally the report provides guidance for nuclear energy organizations for selecting and interpreting safety indicators. It proposes the use of safety culture as a leading safety performance indicator and offers an example list of potential indicators in all three categories. The report concludes that monitor and drive indicators are so called lead indicators. Drive indicators are chosen priority areas of organizational safety activity. They are based on the underlying safety model and potential safety activities and safety policy derived from it. Drive indicators influence control measures that manage the socio technical system; change, maintain, reinforce, or reduce something. Monitor indicators provide a view on the dynamics of the system in question; the activities taking place, abilities, skills and motivation of the personnel, routines and practices - the organizational potential for safety. They also monitor the efficacy of the control measures that are used to manage the socio technical system. Typically the safety performance indicators that are used are lagging (feedback) indicators that measure the outcomes of the socio technical system. Besides feedback indicators, organizations should also acknowledge the important role of monitor and drive indicators in managing safety. The selection and use of safety performance indicators is always based on an understanding (a model) of the socio technical system and safety. The safety model defines what risks are perceived. It is important that the safety performance indicators can help in reflecting on this model. Key questions to ask when selecting and utilizing safety performance indicators are 1) what is required from the nuclear power plant to perform safely and 2) what is required from the organization in order to be aware of its safety level and enhance its safety performance. The indicators should provide information on whether these requirements are met or not, where the organization should put more effort to meet the requirements and finally, does the organization have an accurate view on the requirements